Guest Post by Willis Eschenbach
“Out of passions grow opinions; mental sloth lets these rigidify into convictions”
Friedrich Nietzsche, 1844-1900
Anthony discussed the press release about the paper Past and ongoing shifts in Joshua tree distribution support future modeled range contraction. I didn’t have a copy so I wrote to the lead author, Kenneth Cole, to request one. He responded immediately and sent me a copy. My thanks to him, that’s science at its best. Other than the ritual obeisance to the climate models, the paper tells an interesting story about Joshua trees and the extinct Shasta ground sloths.
The Joshua “tree” is a cactus not a tree, it’s one one of the famous Yucca tribe of cacti spiny spiky things that aren’t cacti according to folks who know better than I do. Calling it a tree is merely the other cactus’s Yucca’s polite way to try to make it feel better about its funny appearance and desolate condition. It grows where almost nobody else can grow, in a very restricted climate range in the American Southwest. Not too hot, not too cold, not too much rain or too little rain, just right.
The fruit of the Joshua tree is a seed pod that was a favorite food of the Shasta ground sloth. The sloth appears to have been the only major seed dispersal mechanism for the Joshua tree. Which is hardly surprising, since other than pack rats and ground sloths, there’ve never been many herbivores hanging out where the Joshua tree grows. It’s way dry in that corner of the US.
The black stars in Figure 2 (from their paper) show the current location of Joshua trees, in and around the Mojave Desert in the hot Southwest.
Figure 2. The authors used rainfall and temperature maps to determine where Joshua trees might possibly grow, with green showing the most favorable climates. Map shows the lower parts of California (left) and Nevada (upper middle), along with a section of western Arizona.ORIGINAL CAPTION: … (A) Suitable climate model for Joshua tree created with mid 20th century (AD 1930 1969) PRISM mean precipitation variables and extreme mean monthly temperature events.
Now, to start with their map is interesting. I mean, the Joshua trees are certainly not growing extensively in what is the best part of the their range according to the authors. Unfortunately, much of the area they say is best for Joshua trees is on Nellis Air Force Base, so there’s no information for large areas. On the other hand, some areas with orange or even red (low probability) have a number of Joshua trees. However, nature is never as neat as we’d like it to be, and they’ve done well to generally outline the range by climate variables. And if it becomes desirable to plant Joshua trees, we know where they’ll likely grow.
Fifteen thousand years ago, in the days of the now-extinct Shasta ground sloth, the geological evidence from pack rat middens and sloth dung shows that the Joshua tree was much more widespread. However, humans happened upon the North American scene around that time, and converted all of the ground sloths into ground slothburgers and barbecued them. Which was bad news for the Joshua trees (not to mention the sloths), because no one else had much taste for Joshua tree seeds. As a result, the range of the Joshua tree is much reduced from its former glory.
The authors also show that the current range of the Joshua trees is further north, and at a higher elevation, than in the times of the ground sloth. During the last ice age the range of the Joshua tree extended across other areas that are now too hot or otherwise unsuitable to support them. As it warmed at the end of the ice age, the Joshua trees retreated (and advanced) to their current locations.
The problem is that without the ground sloths, the Joshua tree’s only seed dispersal mechanism is pack rats. The authors estimated the rate of spread from packrats at two metres per year. This seemed low to me, but is explained in the paper. The missing parts of the puzzle were a) unlike sloths, the packrats only carry the seeds a maximum of about forty metres or so to their homes, and b) the trees take twenty years to reach maturity and produce seeds. Result … 2 metres per year rate of spread. Always more to learn.
So far, so good. And if they’d quit there, it would have been an interesting paper. But no, they had to bring in the climate models. Now, climate models are notoriously bad at predicting precipitation (rain and snowfall). So they figured they’d pick the best of the bunch, viz:
Future downscaled GCM projections
To assess potential future changes in Joshua tree’s suitable climate space we compared future projections from several GCM’s for the late 21st century (2070 2099; ~2X CO2). Five individual models and one ensemble of 48 runs of 22 models based upon the A1B carbon emission scenario were obtained from the Program for Climate Model Diagnosis and Intercomparison (PCMDI; AR4) archive (available online). The five individual models used were: Hadley Center for Climate predic tion (Hadgem1), Max Planck Institute for Meteor ology (Mpi_echam5), CSIRO Atmospheric Research (Csiro_mk3), National Center for Atmospheric Research (Ncar_ccsm3), and Centre National de Recherches Météorologiques (Cnrm_cm3). They were selected because they represent a wide range of future moisture availability conditions for southwestern North America (Seager et al. 2007), and they all were ranked within the top half (of 22 models tested) for their ability to hindcast 20th century precipitation seasonality within the southwestern U.S. deserts (Garfin et al. 2010). These models, especially the Hadgem1 and Mpi_echam5, outperformed most models in replicating the 1950 to 1999 AD geographic distribution of average seasonal precipitation (Garfin et al. 2010).
Then, once they had what they figured were the best five models giving a “wide range” of rainfall results, they ran them and tried to figure where the Joshua trees might live in the future. The models gave differing results, so the authors defined a threshold for suitability (18%). If three of the five models said a particular gridcell would be above the 18% suitablity threshold for Joshua trees, they called it an “area of agreement for future suitable climate (AAFSC)”.
Then they show what those 5 models (and the 22 model ensemble) said would be suitable areas for Joshua trees in the years 2070-2099. Which all sounds vaguely reasonable until we look at their results in Figure 3 …
Figure 3. Results for five models (B-F) and 22 model ensemble (G). Pink areas with thin black outline show current range of the Joshua trees. ORIGINAL CAPTION: … (B G) The Joshua tree future suitable climate model runs for late 21st century (AD 2070 2099 AD): (B) Hadgem1, (C) Mpi_echam5, (D) Csiro_mk3, (E) Ncar_ccsm3, (F) Cnrm_cm3, and (G) Ensemble (44 runs of 22 GCMs).
See, if those results were mine, I’d throw up my hands and say “Not ready for prime time”. Those models are all over the map. They said they picked the models to “represent a wide range of future moisture availability conditions”, but I wasn’t expecting that huge a range. One model is “everything’s fine”, another is “they’re all gonna die!” That’s so wide as to be useless, and these are among the best models.
I don’t see any way that an average of those, or an “AAFSC” of those (area of agreement for future suitable climate), has any meaning at all. One of the models shows a wide area of hundreds of thousands of hectares where the Joshua tree could live, and another shows no suitable area at all.
Finally, once again we have the problem I have called “Models all the way down“. While the model results are interesting, they’ve skipped a big step. I want to see a map, just like the maps above showing possible future distributions of Joshua trees. But I want one showing how well the individual models (and the 22 model ensemble) did at hindcasting the current distribution of the Joshua trees.
I mean seriously – before showing us the model forecasts for 2070-2099 Joshua tree distributions, shouldn’t they show us the model hindcasts for the 1970-1999 Joshua tree distributions? It wouldn’t rescue the paper, but at least it might give some reason to think the selected models might be better than throwing darts at a map of the Mojave region.
Because without that, it’s just models disagreeing and quarreling with each other, all the way down …
w.
I posted a rather intemperate reply to the intolerant bigot Mr Clarke. He deleted it. Fair enough. However another poster supplied some links to a lecture which was very interesting. My response was below. I suspect it will also be censored.
I see you have deleted posts which included a well respected and knowledgeable physicist debating global warming.
I should also say that I do not debate scientologists having a brother who is one or homeopathy but I do have the intellectual rigour to discuss the problems of AGW. And there are many.
In the interests of diversity I’ll repost them so your readers can hear another view. Nothing like diversity
Check out http://www.youtube.com/watch?v=8BQpciw8suk for environmentalists with short attention spans or if you wish to see the whole thing http://www.youtube.com/watch?v=VbR0EPWgkEI&feature=related
Although I agree with the decision to remove “The picture” when asked.
Wouldn’t its continued use be allowed under the Fair Use Doctrine? Especially as the location it was linked from doesn’t claim a copyright or prohibit its use.
Mr Lynn says:
March 30, 2011 at 6:30 pm
Jack Linard says:
March 30, 2011 at 5:46 pm
Who is Chris Clark and why do we care what he thinks?
I try to avoid ad hominems, but this fellow is obviously a complete . . . jerk, and a fool besides.
We don’t care what he thinks. But it is instructive to read his nasty insults just to get a feel for how utterly close-minded the ‘activist’ ideologues really are, and then compare it with the energetic, sometimes opinionated, but generally fair-minded discussion that takes place daily on this blog.
/Mr Lynn
———
I think you forgot to put the /sarc at the end of that sentence…
Can we assume that the shasta sloth ‘seed distribution mechanism’ was similar to that employed by the Asian Palm Civet for Kopi Luwak coffee?
http://en.wikipedia.org/wiki/Kopi_Luwak
A study assessing the utility of biomarker approach to coprolite analysis – and using a
1gm sample from N shastenisis was conducted in 2009.
The dung sample was taken from Gypsum Cave, Nevada, where Harrington (1930)
published ground sloth habitation dated 8500-6500BC and human habitation is dated 3000BC (source wiki)
Table 2 of the article lists the dietary plant saponins specifically epismilagenin
inc Yucca sp which was not published or at the least researched until 1990s
http://www.chm.bris.ac.uk/~chidb/personal/content/paper33.pdf
And why is the question of Pleistocene birds and the collection of seeds (or dung) in nesting/mating habits not discussed? Or are these birds, such as for eg
the bowerbirds of Australia/PNG peculiar to isolated geographical areas or
a later period?
How about someone makes this their hobby – just as sequoias have people who care about them – starts growing them by the hundreds in flower pots and then goes out planting them in the wild in their spare time?
I have a computer model that proves it.
Wow, been around them for years and did not realize that the “Yucca Palm” was really a Joshua Tree. They are all over Florida and even up to the Salt Tolerance zone 2 on the barrier islands. I guess I have seen them as close as 100 yds to the ocean. Not a fragile plant at all.
I remember them most for what the one in our front yard did to a football every year (the oblong spheroid type, not the round ones). We had to patch a football every year because it landed in the yucca. The points could be used for anything you use a pin for. And we would stick them into themselves. The ‘plastic’ skin has that same ‘taste texture’ as a green persimmon, but much less so too.
Oh… I forgot until minutes later. The local name in Central Florida in the 70’s was a Spanish Bayonet. Another reason why the latin nomenclature is always the best way to describe them. But those change too (cichlids are all messed up from when I learned them).
As W. C. Fields would likely say, “Sure I like sloths; fried, baked or boiled; before or after my drink!”
Physics Major says: March 31, 2011 at 7:41 am
Super stuff, post it up please. I’ve always wanted to learn a visual technique based on the study of matter and motion for spotting the correct gender in ambiguous situations.
“Spanish Bayonet” is a different species of yucca.
There are lots and lots of yuccas.
Most–possibly all–depend on the yucca moth for pollination.
The moth comes around and does its thing, laying eggs in the pistil of the plants and picking up pollen to carry around. The growing baby moths, AKA caterpillars, eat fruit pulp, possibly some of the seeds, and later on the fruits are ripe and big moths hatch out…details here I am fuzzy on…
You don’t want to lean on Spanish Bayonet while pulling weeds. It has poor resistance to lateral forces. One of ours fell on my hubby’s head when he leaned on it while yanking out the Johnson grass that had sprouted around its base.
I suspect that both of these things, the moth necessity and the breakage, apply as well to the Joshua tree. Maybe one reason it’s not as widely spread is a decrease in the applicable variety of yucca moths? I’m not at all convinced that these plants are spun glass already.
Best to all
KL
George says:
March 31, 2011 at 7:53 am
Another reason why the latin nomenclature is always the best way to describe them. But those change too (cichlids are all messed up from when I learned them).
####
At least Aequidens and Apistogramma have remained fairly stable, Cichlasoma not so much. For a while, I was finding that I needed to review the literature every few weeks just to keep abreast well enough to support my customers.
Mental sloth and Joshua Trees…..didn`t they both release punk albums in `76?
Visiting a lithium project in northern Nevada last December, I saw some clumps of joshua trees southwest of Tonopah (el 6000′) well north of the maps shown for their range in this article. I didn’t know they were joshuas until I saw a picture of them on WUWT. It seems to me that if you are an expert and want to be seen as such, you should have a better knowledge of their range than an Ontario, Canada rare metals consulting geologist.
I’ve seen this sort of thing before. Fifty years ago, mapping geology for the Manitoba Geological Survey, I had read an article on N.America’s foremost specialist on bald eagles in which he gave their habitat extent as extending into Canada only in a narrow zone along the Rocky Mts. I wrote to him and advised that they occurred virtually across northern Canada and invited him to visit a number of places where he could study them (I later also saw them in Yukon Territory). He wrote back that it was common to mistake them for some other bird, I forget which. I was trying to be helpful but got brushed off. The birds in question were unmistakenly bald eagles and one of the nests was on a small island in a shortish tree and I had to leave the island to the end of the season to map after a very intimidating stand-off while the chicks were still in the nest.
Interesting stuff. I’ve had a look around at the sort of climate that the Joshua tree might appreciate and I think that there are areas in the Groot and Klein Karroo in South Africa which would probably suit.
Has anyone ever considered approaching the S.A. Govt. to ask if a ‘preservation reservation’ for the Joshua might be set up in the RSA?
There might even be some S. A. herbivores which could assist in seed dispersal. Who knows?
Willis Eschenbach says:
March 30, 2011 at 5:16 pm
Kev-in-Uk says:
March 30, 2011 at 3:59 pm
“‘Firstly, if a picture from google is ‘out there’ – shouldn’t his complaint be at least partly directed to them.’
No, it was properly directed here, the action was mine, and we were the ones who could (and did) respond immediately to his request.”
If you did download and store his image on another computer/server and accessed it from there that would constitute infringement, if you don’t have consent.
However it is not illegal by copyright infringement to src his image, as in linking to his site/server, assuming both servers are in the US or in the EU (not in Oz or Kiwi-kingdom neither I believe), since then the client browser is the one doing the connection so to speak. In US this was judged upon by the ninth circuit court a few years ago.
It might be considered to be immoral though since pretty much every poor bastard has to police their own digital property, as in spending time making sure ones property isn’t infringed upon by others. However, if a person has time to spend policing the internet and reading “horrendous” sites such as this, in his case according to him, even the most feeble minded of hippies then has time to learn the basic on how to protect their own digital property, which, incidentally, only needs to be done once.
It’s nice when people are nice but nice is a two way communication. It’s not nice to blame others for ones own incompetence and then go and curse ’em when they’re being nice and complies anyhow.
Why is it that CAGW hippie proponents can’t be civil and nice? Why do they have to blame everyone else for their illiteracy and incompetence?
ddpalmer says:
March 31, 2011 at 5:53 am
Quite possibly. However, the Willis Fair Use Doctrine generally requires me to take down a picture if someone asks …
w.
Chris Clark writing about himself at his blog Coyote Crossing …
“Chris began writing professionally in 1989 for Terrain, a small non-profit monthly environmental publication in Berkeley, CA. He took over the editor’s post there in 1992. By the time he left in 1997 Terrain had acquired a reputation for incisive, intelligent, and iconoclastic writing. Chris has since worked for a number of environmental news publications in print, online and radio, most prominent among them the Earth Island Journal. He’s also been a nationally syndicated garden writer with the Knight Ridder chain, his column generally appearing under the heading “The Irascible Gardener.” His resume is here.”
wow, he’s such a humble guy … and since W. is too nice to say it I will … he’s apparently a foul mouth ignorant ex-gardener with a huge chip on his narrow shoulders …
Nietzsche was a teacher’s nightmare. A lot of people don’t know this, but when he was a kid, if you handed him some scissors, he’d run around like his pantaloons were on fire. He simply would not abide by the then current theory that you shouldn’t run with scissors.
It makes me wonder how awesome he’d be when discussing AGW. I’m guessing ‘pretty awesome’.
Like averaging temperatures from disparate locales: it proves you can do arithmetic, but says nothing whatever about the physical world.
How can you possibly mistake a bald eagle for anything else? Their white heads and chocolate brown bodies are practically unmistakable. Besides, those enormous nests are unique in the natural world.
The writer mentions Shasta ground sloths and pack rats as being just about the only two herbivores in the arid regions where the Joshua Tree grows, but in fact there are others including feral horses, tortoises, antelope, deer, and even elephants. Of course I’m referring to the inventory of animals prior to the great extinction event at the boundary between the pleistocene and holocene. Whatever caused it is still an uncertainty, but that they, or their surrogates, could and do still survive and would add to the productivity of the trophic levels is not much disputed. I think we should be actively re-introducing species and their surrogates while reducing the numbers of domestic cattle that graze our wild public lands in the southwest.
doug l says:
April 2, 2011 at 11:31 am
You raise an interesting question, Doug. It’s not clear to me exactly what species would thrive, or even survive, in the conditions where the Joshua trees live. What species would you consider introducing to the area? I’ve read that the Early Asian Immigrants (aka American Indians, aka Native Americans) used to eat the seeds of the Joshua trees …
Thanks for the ideas.
w.